North Korea will eventually have nuclear-armed missiles capable of reaching all of its adversaries despite a recent string of technological failures, according to the latest warning from a top U.S. military official.

The commander of U.S. Pacific Command's Army forces, Gen. Vincent Brooks, testified Tuesday before the Senate Armed Services Committee and shared a bleak assessment of rising tensions on the Korean Peninsula.

"They're struggling with getting the program up and operational," Brooks said when asked about Pyongyang's efforts to build intercontinental ballistic missiles. "Over time, I believe we're going to see them acquire these capabilities if they're not stopped."

Nominated to lead U.S. Forces in South Korea, Brooks said that it would be his job to provide options for how the U.S. could use military pressure to change the North Korean calculus.

FILE - North Korean leader Kim Jong Un looks at a rocket warhead tip after a simulated test of atmospheric re-entry of a ballistic missile, at an unidentified location in this undated photo released by North Korea's Korean Central News Agency.

"North Korea is moving in the wrong direction, and the changes that we've seen are all provocative and more dangerous — their willingness to draw blood, to sink vessels, to fire some of their numerous artillery systems into populated areas," he said.

Kim, undeterred

When asked by Senate Armed Services Committee Chairman John McCain, a Republican, about the "immaturity and the unpredictability of the rotund ruler in Pyongyang," Brooks responded that it is clear that North Korean leader Kim Jong Un "is not yet deterred."

Brooks also warned that continued purges of North Korea's military leadership show Kim is unwilling to take advice.

Still, there are questions about how long it will take for North Korea to acquire a full range of nuclear weapons capabilities.

U.S. officials called a test earlier this week of a road-mobile ballistic missile on North Korea's east coast a "fiery, catastrophic" failure. Others say Pyongyang, while aiming for significant capabilities, has yet to demonstrate it can get key aspects of the technology to work.

There have also been indications that the pursuit of high-end technology, including submarine-launched ballistic missiles, has hurt the ability and readiness of North Korea's conventional forces.

FILE - One of four U.S. F-22 stealth fighters lands at Osan Air Base in Pyeongtaek, South Korea, Feb. 17, 2016. Four U.S. F-22 stealth fighters flew over South Korea in a show of power against North Korea.

"This is like watching someone ride a bike, but falling off of it," Brooks told lawmakers. "Eventually, they can become a BMX champion. We can't underestimate the hazard that is emerging on this."

‘Very dangerous’ prospect

Pyongyang's slow but undeterred progress comes despite increased pressure from the international community, including a new round of tougher U.N. sanctions adopted last month.

Officials fear one reason North Korea has been able to move forward with its nuclear and missile programs is that China, a long-time supporter of the regime in Pyongyang, has failed to do enough to crack down.

Brooks said senior Chinese military leaders have told him that they, too, are frustrated.

"There are challenges that have been expressed to me by the senior Chinese military leadership that they don't have the influence they once had," Brooks told lawmakers.

"I would want to challenge that," he said. "I do believe they have opportunities to influence [Pyongyang] greater than they have."

Brooks also said there is "some evidence" North Korea is getting help from Iran, a prospect he said was "very dangerous for the world, very dangerous for the region."